In serial asynchronous communication between a transmitter and a receiver it is required that the transmitter and the receiver are synchronized. Since the local oscillator in the transmitter and the local oscillator in the receiver typically operate at frequencies that are slightly different, e.g. due to imperfections or deliberately to reduce electromagnetic emission, there is typically a frequency drift between the transmitter and the receiver that may cause the requirement for a re-synchronization after a certain period of communication. It is desirable to reduce the number of necessary re-synchronizations.